Triturating member



Aug. 34, 1923.

Filed Jan. 1'7 1922 ATTORNEY type.

Patented Aug. 114, 1923..

'UNTTEID) STATES PATENT ()FFMCEO ARTHUR JFEUST, OF NEW YORK, N. 2.

TRITURATING MEMBER.

Application filed January 1 To all whom it may concern:

Be it known that l, ARTHUR FEUsr, a citizen of the United States, andresident of the borough of Manhattan, city, and State of New York, haveinvented a certain new and useful Triturating Member, of which thefollowing is a specification.

This invention relates to grinding mill balls,and to mills of the balland drum.

. An object of the invention is to provide a novel triturating memberfor such mills to take the place of the balls heretofore used. In theoperation of such mills with round balls, the material is always left inrelatively large particles largely because only a grinding action takesplace, and when such materials are ground to the greatest practicablefineness in mills containing round balls, they invariably feel gritty.With the use of this invention, rock materials may be pulverized sofinely as to feel,- smooth to the touch. In other words, the presentinvention operates with a trituratlng action as distinguished from therolling action of mills of the ball and drum type as heretoforeemployed.

Another object of the invention is to provide triturating members orelements which themselves ,wear uniformly in consonance with theiroriginal shape so as toretain sub stantially their original shape afterlong continued use, and thus throughout their life operate and functionunder the same fundamental laws shape.

It has also heretofore been proposed to employ grinding elements otherthan round balls in mills of the ball and drum type in the hope ofadding to their grinding action a triturating action and thus breakingup the material so that it will pass through a fine mesh. For instance,it has been proposed to use pebbles of irregular shapes, ob-

ong rectangular blocks having plane sides, and lenticular disk-shapedand ovaloid grinding devices. None of these devices, however, operatescontinually with a triturating action, and their object was thereforefrustrated. Moreover, such devices, as heretofore tion that they do notwear uniformly consonant with their original shape in conse quence ofwhich the character and extent of their grinding action varies greatlywith the length of their use. For the above and governing their originalproposed, have the serious objec- 7, 1922, Serial No. 529,867.

other reasons, none of such modified forms of grinding elements has goneinto general use, so far as applicant is aware.

1 in lrnportant feature of the invention resides 1n the provision of atriturating element adapted for use in a mill of the ball and drum typeand having a substantially circular basic configuration withsubstantially paraboloidal and ellipsoidal sections perpendicular toeach other and to the basic circular section so as to provide oppositelydisposed triturating surfaces. In defining the invention in terms ofsubstantially circular, substantially paraboloidal and substantiallyellipsoidal dimensions, 1' do so with the understanding that I am notconfined to geometrical exactitude, as if use such terms to portray thefunctional law inherent in such configuration.

Other objects and features of the invention will appear as thedescription proceeds and will be pointed out in the appended claims.

In the drawings:

Fig. 1 is a view in side elevation of the improved triturating elementand showing the lower portion of the element in section;

Fig. 2 is a plan view of the element, showing the element in section inthe lower part of the figure;

Fig. 8 is a view in vertical transverse section along the line 33 ofFigs. 1 and 2; and

Fig. st is a view in section along the line 4-4 of Figs. 1 and 2 andlooking in the direction of the arrows.

Similar reference characters indicate similar parts in the severalviews.

As illustrated in the drawing, the basic dimension of the trituratingelement 10 is circular. ln planes at right angles to the basic circulardimension or main section of the element, which is in the plane of ahorizontal line drawn through the middle of Fig. 1, the sections in onedirection through the element are paraboloidal, and in planes at rightangles thereto are ellipsoidal. The general exterior configuration ofthe element resembles very closely the exterior configuration of a seaclam excepting that the sharpened edges of the month are rounded off. Asthe clam has its centroid oft center, so the new triturating element hasit centroid oft center, that is, its center of volume or gravity is offcenter with respect to its center of figure. In general also the move-Ill reference to Figures 2,

ment of the element down an inclined plane closely resembles that of aclam. In the drawing the end surface at the base of the element isdesignated by 12, and its upper and lower surfaces by the numerals 14and 16. Although the surfaces 14 and 16 do not lie in a plane but areslightly curved longitudinally, as clearly appears from. Figures 1 and4, they may be said to be flattened with respect to the other surfacesof the element, since the degree of their curvature is very smallcompared with the curvature of the base portion 12 and the circularsection of the element.

The surfaces 14 and 16, as will be seen by 5, 6 and 7, are also slightlycurved in sections element as well as in longitudinal sections, thesurfaces 14 and 16 of relatively slight curvature being interposedbetween edge surfaces 18 and 20 of relatively sharp curvature. Theentire surface of the element is uninterruptedly curved, the portions ofthe surface of varying curvatures merging into each other without anydefinite line of demarcation.

IVhen a number of triturating elements constructed in accordance withthis invention are contained in a rotating drum, their surfaces 14 and16 of relatively slight curvature prevent them from rolling over eachother after the manner of round balls and instead thereof cause them tohave a sliding movement one upon another. In addition to andsimultaneous with their sliding move-' ments, the triturating elementsalso undergo relative turning or twisting movements,

such relative turning movements combined with their sliding movementscausing them to'act with a triturating efiect on the material beingground. I

It will be apparent from the foregoing that the triturating elements areconsiderably heavier at one of their ends than'at the other, whichfollows because their centroids are-ofi center, the elements being inequilibrium on a downwardly inclined surface only when their heavierends are lowermost. The movement of the drum and the forces exerted onthe elements by each other and by the material being ground cause themto be ofi-balance almost, if not quite, continuously during theoperation of the mill. Whenever an element is thrown into an unbalancedposition, it tends to recover its equilibrium. If an element is notsubjected to other forces during its return to balanced position, itwill move somewhat after the manner of a pendulum or a clam on aninclined surface. In other words, the heavier end of the element willswing first to one side and then to the other.

The very considerable and practically continuous turning movements ofthe elements of this invention, which result from their transverse tothe being thrown out of a position of equilibrium and tending to returnto such position, is very important in causing them to act with atriturating efiect on the material being ground. The triturating actionof the elements is also enhanced by the fact that when the slightlycurved surface 14 or 16 of one of them is in contact with the surface 14or 16 of the adjacent element, the surfaces of the elements diverge verygradually from their contact point. Such arrangement of the surfaces notonly provides a large active zone, but a zone in which the intimateassociatlon of the surfaces causes balls is very limited and no grindingaction is exerted on a small particle between the balls unless suchparticle happens to be practically at the contact point. Moreover,inasmuch as the contacting surfaces of two round balls are substantiallysimilar, the balls are likely to assume a condition of equilibrium withwhich they have little or no tendency to slide one upon the other. Inthe use of a grinding mill containing the elements of the presentinvention, adjacent elements will generally contact with each other atthe slightly curved surfaces 14 and 16. In the event, however, that oneof the more sharply curved ortions of one of the elements contacts withthe surface 14 or 16 of the adjacent element, the active zone betweenthe two elements will be much larger than if the elements wereconstructed in the form.

of round balls. Furthermore, the firstmentioned element will tend toslide upon the lightly curved surface of the second element, curvedsurfaces of the elements into substantial contact and producing therebya triturating action. The elements having their main or longitudinalsections circular and having tapering surfaces such as have beenhereinbefore described will wear uniformly in oonsonance with theiroriginal shape and will consequently retain substantially their originalshape even after long continued use. As a result of this, thefunctioning of the I ele-' ments will be the same throughout the life ofthe elements. en, however, other forms of elements having taperedsurfaces,

but not having their main sections circular were tried out, it was foundthat they did not wear uniformly. Y

This invention is particularly applicable thereby bringing the slightlyrespect to each other in I have described the elements in terms ofcircular, paraboloidal and ellipsoidal con-' figuration. I have donethis to portray the preferred embodiment with accuracy to enable thoseskilled in the art to construct elements in accordance with myinvention. It is, of course, clear that an element having suchconfiguration will function in accordance with certain definite laws andthat a principle of the invention is readily perceived therefrom. Byusing the word substantially as definitive of these configurations, Idesire to include all such elements that operate within said principleof the invention, as otherwise a geometrical limitation would not fullyprotect my invention, and so desire it to be understood that Icontemplate within such definitive terms a reasonable equivalence.

Having fully described the invention, what is claimed is:

1. A tumbling element for tube mills, said element being substantiallydisk-shaped in plan and having a, rounded peripheral edge and decreasingin thickness along curved lines from a point on one side of the centerof the plan thereof to all points at its peripheral edge.

2. A tumbling element for tube mills, said element being substantiallydiskshaped in plan and having a rounded peripheral edge and decreasingin thicknessalong curved lines from a point on one side of the center ofthe lan thereof to all points at its peripheral edge, and having itscentroid ofl center.

3. A tumbling element for tube mills, said element being substantiallydisk-shaped in plan and having a rounded peripheral edge and decreasingin thickness along curved lines from a. point on one side of the centerof the plan thereof to all points at its eripheral edge, and having a,substantially paraboloidal section extending from end to end of theelement and being substantially ellipsoidal in sections transversely ofthe element so as to present oppositely disposed triturating surfaces.

a. A tumbling element for tube mills, said element being substantiallydisk-shaped in plan and having a rounded peripheral edge and decreasingin thickness along curved lines from a point on one side of the centerof the plan thereof to all points at its peripheral edge, and havingunlnterrupted, merging curved surfaces, and the element beingsubstantially paraboloidal and ellipsoidal respectively in sections atright angles to the plan and to each other.

lln testimony that I claim the foregoing as my invention, 1 have ned myname a THUR FEUST

